1. Field of the Invention
The present invention relates to a one-pack curing type composition which is cured by moisture in the air. More particularly, it relates to a one-pack curing type composition comprising as indispensable components a polymer containing at last two silylthioether linkages in the molecule and an oxidizing agent, which is naturally cured by moisture in the air and is utilizable as a sealing material and the like.
2. Description of the Related Art
Since a polymer having at least two thiol groups in the molecule can be easily converted to a higher polymer by oxidizing the contained thiol groups to form a disulfide linkage, this polymer is combined with various oxidizing agents and widely used as a sealing material, a caulking material, an adhesive and the like.
As the thiol group-containing polymer of this type, there can be mentioned a liquid polysulfide polymer disclosed in U.S. Pat. No. 2,466,963; a thiol-terminated polyoxyalkylene polyol disclosed in Japanese Examined Patent Publication No. 47-48,279; a polymercaptan disclosed in U.S. Pat. No. 4,092,293; a mercaptan-terminated liquid polythioether disclosed in U.S. Pat. No. 4,366,307; a poly(oxyalkylene)polyester-poly(monosulfide)-polythiol disclosed in Japanese Examined Patent Publication No. 52-34,677; a butadiene-mercaptan polymer disclosed in U.S. Pat. No. 3,282,901; a mercaptan-containing polymer disclosed in U.S. Pat. No. 3,523,985; and, a mercapto-organopolysiloxane disclosed in Japanese Examined Patent Publications No. 55-39,261 and No. 60-3,421.
These thiol group-containing polymers are mixed with various inorganic peroxides, organic peroxides, polyepoxy compounds, polyolefin compounds or polyisocyanate compounds and are used as curing compositions. However, in practical applications, these compositions are generally used in the form of a two-pack type composition, wherein a main component and a curing agent are stored separately.
As the one-pack type composition comprising a thiol group-containing polymer as the main component, there are known a composition utilizing an amine-adsorbed molecular sieve, as disclosed in Japanese Examined Patent Publication No. 42-11,502, and a composition utilizing a curing system using oxygen in the air, as disclosed in Japanese Examined Patent Publication No. 47-48,279 or No. 60-3,422. The former composition has a problem, however, such that in order to maintain a good storage stability and, simultaneously, ensure a high curing rate after application, an advanced technique is necessary for selecting an oxidizing agent or incorporating a curing catalyst, and in the case of the latter composition, if the oxygen permeability of a composition is low, curing is not advanced to the interior thereof, and the kinds of applicable polymers are limited.